The present system relates to cellular telephones, and specifically to adaptive adjustment of sleep duration in such a cellular telephone.
A Code Division Multiple Access (CDMA) paging channel transmitted by a base station is divided into slots. A cellular telephone, often referred to as a mobile station, operating in the slotted mode only needs to monitor its own slot for messages and may xe2x80x9csleepxe2x80x9d at other times to increase standby time.
When the cellular telephone, or xe2x80x9cmobile station,xe2x80x9d is not engaged in a call, the mobile station does not continuously monitor the paging channel. It spends a percentage of its time in a low power state to save power. When in these low power states between paging channel slot cycles, the mobile station shuts off all non-essential circuitry. These low power idle periods conserve power and prolong battery life. However, the mobile station needs to maintain reasonably good response time for keypad presses, data cable traffic, and other input/output (I/O) signals. Therefore, the mobile station circuitry often remains active even during idle periods. This drains power from the battery.
In recognition of the above, the inventor has developed a system for a wireless mobile station that enables the mobile station to adaptively adjust sleep durations and wakeups during a low power idle mode between paging channel slots. The adjustment of sleep durations and wakeup intervals are based on a number of key-presses or other input/output (I/O) activities within a fixed number of paging channel slots. The adjustment increases standby time for the mobile station.
In one aspect, the sleep duration adjustment system includes a counter, a processor, an expiration time register, a timer, and a signal generator. The processor adjusts sleep durations and wakeups based on a number of key-presses or other input/output (I/O) activities within a fixed number of paging channel slots. The counter is configured to count a number of clock cycles from a last wakeup. The counter allows adjustment of sleep durations by fixing the number of clock cycles before a next wakeup. The timer allows the mobile station to have at least two states with different sleep durations and wakeups between the paging channel slots. The expiration time register holds an expiration time for the timer. The register indicates when to transition from one state to another state of the two states. The signal generator generates a transition signal to transition the mobile station from one state to another state when a time kept by the timer reaches the expiration time stored in the expiration time register.
In another aspect, a method of increasing standby time in a wireless mobile station is disclosed. The method involves starting a timer containing a time value when an input is received. The mobile station is placed into a first state with a first sleep duration. The mobile station is then transitioned into a second state with a second sleep duration when the time value reaches a pre-specified value. The second sleep duration is longer than the first sleep duration.
In a further aspect, a wireless telephone device is disclosed. The device includes a housing, and a sleep duration adjustment system within the housing. The system adaptively adjusts sleep durations and wakeups during a low power idle mode between paging channel slots based on a number of key-presses or other input/output (I/O) activities within a fixed number of said paging channel slots. The adjustment increases standby time for the telephone device.